- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - HP-UX
- >
- Re: Test write performance found error
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 01:53 AM
тАО01-25-2011 01:53 AM
I want to test disk write performance as below, the result is found error, and to check /dev/vg00/lvol6 becomes full, why it happened? If I want to test write and read performance, what command will it be performed? Thanks in advance!
that is "time dd if=/dev/zero of=/tmp/sysinfo.tgz " should not be used in disk write performance ?
root@test:/tmp # time dd if=/dev/zero of=/tmp/sysinfo.tgz
msgcnt 2 vxfs: mesg 001: vx_nospace - /dev/vg00/lvol6 file system full (1 block extent)
I/O error
5802049+0 records in
5802048+1 records out
real 3:19.7
user 2:28.4
sys 45.4
# bdf
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol3 4194304 490408 3675048 12% /
/dev/vg00/lvol1 1014648 160680 752496 18% /stand
/dev/vg00/lvol8 8388608 4898488 3490120 58% /var
/dev/vg00/lvol7 20971520 2597736 18230280 12% /usr
/dev/vg00/lvol6 16777216 16777216 0 100% /tmp
/dev/vg00/lvtmp01 1638400 1502 1534599 0% /tmp/prd001
/dev/vg00/lvol5 8388608 3608408 4742888 43% /opt
/dev/vg00/lvol4 2097152 26648 2054368 1% /home
Solved! Go to Solution.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 03:32 AM
тАО01-25-2011 03:32 AM
Re: Test write performance found error
>msgcnt 2 vxfs: mesg 001: vx_nospace - /dev/vg00/lvol6 file system full (1 block extent)
This will write until the FS is full. You need to limit the count:
count=n
You could also pick bigger block sizes:
bs=1024k
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 03:37 AM
тАО01-25-2011 03:37 AM
Re: Test write performance found error
I sugest that uses for your output file (of) a target that have enough free space to place the input file (if) inside, or uses a infinite device as /dev/null. Seems that you are mixed up the "if" and "of" entries order, so just try:
root@test:/tmp # time dd if=/tmp/sysinfo.tgz of=/dev/null
The "sar" command will be useful to trace disk performance (man sar).
#sar -d 5 100
Rgds.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 09:44 AM
тАО01-25-2011 09:44 AM
Re: Test write performance found error
If you want to "test" how fast a filesystem can perform writes - then you need to TELL your tool how much to write to avoid filling up the filesystem. You also need to specify a "block size" since there are certain block sizes that are apropo for certain filesystems.
dd if=/dev/zero of=/path/file.dat bs=1024k count=1024
(will perform a write at 1MB block sizes for a total of 1GB, 1024 blocks). Note that repeating the test will likely give you a very fast performance due to Filesystem caching...
You can also use the peralloc command:
prealloc /tmp/test.dat 1000000000
will create a file size 1 billion bytes.
Note it will also be affected by cache so subsequent execution will yield very fast results.
Now a word on /tmp (or even /var/tmp) as applications temp space:
If /tmp or /var/tmp are part of your OS disk and yor OS disk is a local SCSI or RAIDED scsi disk -- that your app performance will be severely affected specially IF I/O requirements are steep... Invest on:
- having your OS be on SAN disks
- have your APPs TMPDIR or whatever environmental variable point to a SAN Disk filesystem
- Use SolidState SSD Disk for your OS or /tmp space.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 05:17 PM
тАО01-25-2011 05:17 PM
Re: Test write performance found error
Very very thanks for all response, I see it now, but who can introduce these special file and its usage as below, thanks!
/dev/zero
/dev/null
/dev/full
/dev/random
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 05:46 PM
тАО01-25-2011 05:46 PM
Re: Test write performance found error
I suppose /dev/dsk/c0t0d0 is root disk,
if it run below command, this disk will be damaged ?
dd if=/dev/zero of=/dev/dsk/c0t0d0 bs=8k count=8192
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 06:56 PM
тАО01-25-2011 06:56 PM
Solution> I suppose /dev/dsk/c0t0d0 is root disk,
if it run below command, this disk will be damaged ?
> dd if=/dev/zero of=/dev/dsk/c0t0d0 bs=8k count=8192
The disk will not be damaged, BUT YOU WILL DESTROY ALL DATA ON YOUR ROOT DISK!!! Your system will no longer boot up and you will have to cold install everything on the root disk.
> introduce these special file and its usage as below, thanks!
> /dev/zero
/dev/zero provides an unlimited string of zeros.
> /dev/null
Often called the bit-bucket, this device file provides a destination for unlimited amounts of data -- the data is discarded. When used as input, it provides nothing but and end-of-data signal, that is, no data at all.
> /dev/full
Reading from this device will always succeed and report that the requested number of bytes were read. However, no data will actually be copied to the read buffer.
> /dev/random
This provides a random integer. It is not suitable for unlimited strings of random numbers as it will block when the string is long. Use /dev/urandom for longer strings.
Bill Hassell, sysadmin
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-25-2011 11:59 PM
тАО01-25-2011 11:59 PM
Re: Test write performance found error
Thanks for your response,
as your points,if it runs below command, /tmp/sysinfo.tgz file will lose part of data, right ?
if yes, how to ensure the data integrity through command "dd if=/dev/zero of=/dev/rdsk/cxtxdx" for disk write performance?
root@test:/tmp # time dd if=/dev/zero of=/tmp/sysinfo.tgz count=1000
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-26-2011 12:16 AM
тАО01-26-2011 12:16 AM
Re: Test write performance found error
Please try to understand that this will overwrite the complete disk, so you loose all the data!
Hope this helps!
Regards
Torsten.
__________________________________________________
There are only 10 types of people in the world -
those who understand binary, and those who don't.
__________________________________________________
No support by private messages. Please ask the forum!
If you feel this was helpful please click the KUDOS! thumb below!
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО01-26-2011 01:51 AM
тАО01-26-2011 01:51 AM
Re: Test write performance found error
Okay, I see it will overwrite the complete disk for dd if=/dev/zero of=/dev/rdsk/cxtxdx, my exact question should be,if it runs command "dd if=/dev/zero of=/tmp/sysinfo.tgz count=1000 bs=512kb", /tmp/sysinfo.tgz file will be overwrite part of original data, right ? Base on the premise that /tmp leave more than 500 MB space!